Torque override threaded locking cap

ABSTRACT

A locking cap for a threaded filler neck includes a closure member for engaging and closing the neck, a shell providing a hand grip and including a key-actuable lock, and a race disposed for rotation between the shell and closure. The race includes axially inwardly opening pockets, and the closure includes flexible pawl fingers for engaging the pockets to provide a driving connection between the closure and race which is positive in the cap-removal direction and torque-limited in the cap-advancing direction. The race also includes a set of peripherally spaced, radially inwardly projecting teeth, and the shell is molded to provide a pair of flexible drive fingers for engaging the peripherally spaced and radially inwardly projecting teeth to provide a driving connection between the shell and race which is positive in the cap-advancing direction and torque-limited in the cap-removal direction for free ratcheting of the cap when it is in position on the filler neck and locked. A lock-controlled bolt member mounted for rotation with the shell is movable by the lock to a cap-removal position. The bolt member engages driving teeth provided within the closure member. The driving teeth are formed such that rotation of the shell in the cap-advancing direction, after the lock has been returned to the cap-locking position, cams the bolt out of engagement with the driving teeth.

This invention relates to closure caps for vehicle fuel tank threadedfiller necks, and particularly to a locking cap having a substantiallyall-plastic construction and a low axial profile.

Various types of locking gas caps for vehicle fuel tank threaded fillernecks are known. See, for example, Summan, U.S. Pat. No. 4,000,632;Evans, U.S. Pat. No. 4,000,633; Sloan Jr., U.S. Pat. No. 4,083,209;Evans, U.S. Pat. No. 4,107,961; and German OLS No. 2,014,130.

It is an object of the present invention to provide a locking cap for athreaded filler neck which is simple and easy to manufacture. Theapparatus of the instant invention is constructed largely of moldedplastic parts, and is very rugged and sturdy.

According to the invention, the locking fuel tank filler neck capincludes a closure member for threadedly engaging and closing the neck,a shell providing a hand grip and including means for retaining akey-actuable lock, and a race disposed for rotation between the shelland closure. The race includes first engaging means and the closureincludes second engaging means for engaging the first engaging means toprovide a driving connection between the closure and race which ispositive in the cap-removal direction and torque-limited in thedirection which advances the cap on the neck. The race further includesa third engaging means, and the shell includes a fourth engaging meansfor engaging the third engaging means to provide a driving connectionwhich is positive in the cap-advancing direction and torque-limited inthe cap-removal direction. The cap further includes bolt means rotatablewith the shell and controlled by the lock, and fifth engaging meansprovided on the closure for engagement by the bolt supported by the boltmeans when the lock is moved to the cap-removal position, to permitremoval of the cap. The lock may be returned to the cap-locking positionwithout resulting in disengagement of the bolt from the fifth engagingmeans. This permits the key to be removed from the lock before the capis replaced on the filler neck, a desirable feature in locking caps ofthis type. However, once the closure is turned in the cap-advancingdirection a predetermined amount, the bolt encounters camming surfaceson the fifth engaging means and is cammed out of engagement with thefifth engaging means.

In the illustrative embodiment, the first engaging means comprises atleast one axially opening pocket including an inclined camming surfaceand a locking surface, and the second engaging means comprises at leastone flexible finger on the closure, the finger being formed to providean axially deflectable pawl having an inclined camming surface and alocking surface. The camming surfaces and flexible finger cooperate toprovide the torque-limited connection between the closure and race inthe cap-advancing direction. The locking surfaces cooperate to providethe positive connection between the closure and race in the cap-removaldirection.

Further in the illustrative embodiment, the third engaging meanscomprises at least one radially inwardly projecting engaging tooth on aradially inwardly facing surface of the race, the tooth including aninclined camming surface and a locking surface. The fourth engagingmeans includes at least one flexible finger projecting into engagementwith the tooth, the finger including a camming surface and a lockingsurface. The camming surfaces of the tooth and finger and theflexibility of the finger cooperate to provide the torque-limitedconnection between the race and shell in the cap-removal direction andthe locking surfaces thereof cooperate to provide the positiveconnection between the race and shell in the cap-advancing direction.

The instant structure permits a low axial profile for the threaded fueltank filler neck cap. This cap requires less space for the apparatusrequired to operate the unlocking and cap-removal mechanism. The shellincludes a portion which is integrally and unitarily molded withflexible fingers forming a part of the unlocking mechanism. Much of thecap of the instant invention can be constructed from molded plastic. Adistinct advantage of this construction is that such parts can be madequite inexpensively in two-part molds.

The invention may best be understood by referring to the followingdetailed description and accompanying drawings which illustrate theinvention. In the drawings:

FIG. 1 is an axially sectional side elevational view of a threadedlocking gas cap constructed according to the present invention;

FIG. 2 is a fragmentary sectional view of the cap of FIG. 1, takengenerally along section lines 2--2 thereof, and showing the lock in anunlocking, or cap removal, position;

FIG. 3 is a fragmentary sectional view of a detail of the cap of FIG. 1,taken generally along section lines 3--3 thereof;

FIG. 4 is a fragmentary sectional view of a detail of the cap of FIG. 1,taken generally along section lines 4--4 of FIG. 3;

FIG. 5 is a fragmentary sectional view of the cap of FIG. 1, takengenerally along sections lines 2--2 thereof, with the lock mechanism ina locking position; and

FIG. 6 is an exploded perspective view of a portion of the capmechanism.

Referring now particularly to FIG. 1, the locking cap 10 includes amolded plastic closure member 12 having an axially inwardly extendingshank portion 14 which is threaded as indicated at 16 to engage athreaded filler neck 17. Closure 12 includes a gasket 18 which sealablyengages the conventional peripherally and radially outwardly extendinglip provided by the filler neck 17. Closure 12 further includes apressure-vacuum vent valve housing 19 into which is assembled apressure-vacuum vent valve assembly 20. Assembly 20 controls venting ofpressure and vacuum which develop within the fuel tank in a manner whichis well-know. The valve assembly 20 is retained within housing 19 by acover plate 22 which is press fitted into the axially outer end 24 ofhousing 19. Closure member 12 further includes an annular supportingwall 26 axially outwardly from housing 19. A generally cylindrical wallregion 28 is defined within the axially outer end 30 of closure 12.

Generally cylindrical wall region 28 is provided with a plurality ofradially inwardly extending engaging teeth 31 (see FIG. 2). Each tooth31 includes a generally radially and axially extending locking surface33 and a generally chordally and axially extending camming surface 35.Closure 12 also includes a flange 32 at its axially outer end. Flange 32extends radially outwardly of the axis of closure 12, and includes fourperipherally extending resilient fingers 34 (see FIG. 2). Fingers 34 areattached at their proximal ends to flange 32, and are provided at theirdistal ends with pawl teeth 36. Each tooth 36 has an inclined cammingsurface 38 and a radially and generally axially extending lockingsurface 40.

Cap 10 further includes an annular race 42 (see FIGS. 1, 3) which isdisposed for rotation within the cap. As can be seen from FIG. 1, race42 lies directly axially outwardly from flange 32. Race 42 includes aset of peripherally spaced apart, axially inwardly opening pockets 44(see FIG. 3). Each of pockets 44 includes an inclined camming surface46, and a radially and axially extending, abrupt locking surface 48.Surfaces 38, 46 of teeth 36 and pockets 44, respectively, cooperate toprovide a torque-overriding connection of race 42 to closure 12 in thedirection (counterclockwise in FIG. 3) which advances closure 12 intothe fuel tank filler neck. Surfaces 40, 48 of teeth 36 and pockets 44,respectively, cooperate to provide the direct connection of race 42 toclosure 12 in the direction (clockwise in FIG. 3) which removes closure12 from the filler neck.

Race 42 also includes a radially inwardly facing, peripherally extendingsurface 45 which is provided with four radially inwardly extendingprojections 47. Each projection 47 includes an abrupt radially andaxially extending driving face 49, and an inclined camming surface 51.

Cap 10 further includes a molded plastic shell member 50 (see FIG. 1)secured to closure member 12 for rotation with respect to the closuremember about the axis of cap 10. Race 42 is captured in an annular spaceprovided between shell member 50 and closure 12. Shell member 50 isprovided with a central axial opening 52 to accommodate a cylinder lockassembly 54. The cylinder lock assembly 54 is retained within shellmember 50 by a locking lug 56 which projects radially outwardly fromassembly 54 near its axially inner end to engage a radially inwardlyextending cylindrical wall portion 58 of shell member 50. Lock assembly54 includes an axially extending drive pin 60 which projects from theaxially inner end of the lock assembly, and which is actuated by turningthe key 61 (FIG. 1) in the lock assembly 54 to move drive pin 60counterclockwise as viewed in FIG. 2 (from the position illustrated inbroken lines to the position illustrated in solid lines) to conditionthe cap 10 for removal from the filler neck.

Cap 10 further includes a locking bolt mechanism 62, which is bestillustrated in FIGS. 2, 5, and 6. Bolt mechanism 62 includes a generallycup-shaped portion 63, and includes axially outwardly extendingprojections 64 diametrically disposed about the upper annular edge 66 ofcup-shaped portion 63 (FIGS. 1, 3, and 6). Projections 64 extend intothe molded plastic shell portion 50. The bottom 68 of member 62 isprovided with a pair of chordally extending guides 70 defining a boltslideway 72. A bolt 74 having an enlarged and somewhat rectangularprism-shaped head 75 is slidably guided in the slideway 72 and is heldin the slideway by the bottom 68 of portion 63 and the closely spacedaxially inner end 76 of the lock assembly 54. Head 75 defines a notch 77having dimensions such that rotation of key 61 to the cap-removalposition moves the bolt 74 to the position illustrated in FIG. 2. Thebolt head 75 further includes a resilient spring-like projection 78which extends generally longitudinally of the slideway 72 across portion63. The generally cylindrical interior wall 79 of portion 63 is providedwith an axially extending blocking ridge 81 which cooperates with thehead 83 of projection 78 on bolt 74 to hold the bolt yieldably in eitherof two positions which will be described.

Referring now to FIG. 3, a bottom plan view of shell member 50, it willbe seen that the outer end 80 of shell member 50 is provided with a pairof windows 82. Windows 82 extend axially through the outer end 80 ofshell member 50. A pair of axially inwardly extending projections 84(FIGS. 3-4) are molded on the axially inner surface 86 of end 80.Axially extending surfaces 88 of projections 84 are coterminous with endedges 90 of windows 82. Resilient molded drive fingers 92 project fromsurfaces 88 within windows 82. Fingers 92 extend generally along chordsof a circle defined by shell member 50. Windows 82 enable fingers 92 tobe molded in a simple, two-part mold. Fingers 92 include radially andaxially extending engaging surfaces 94 and camming surfaces 95 at theirdistal ends. The outer end 80 of shell member 50 also includes a pair ofdiametrically opposed windows 100. Projections 64 extend through windows100 (see FIGS. 1 and 3) to lock bolt mechanism 62 for rotation withshell member 50.

Closure 12, race 42 and shell member 50 are held in relatively rotatableengagement by a retainer ring 110 (of FIG. 1) and shell cover 112. Ring110 and shell cover 112 are both constructed from stamped sheet metal,with a depending skirt portion 114 of shell cover 112 being crimped asat 116 to hold ring 110 axially outwardly against the axially innersurface 118 of flange 32. A plurality of radial and axial indentations120 are stamped into shell cover 112. These indentations 120 correspondin their peripheral locations with a plurality of similar indentations122 which are molded into shell member 50. Engagement of indentations120, 122 prevents rotation of shell cover 112 with respect to shellmember 50. The axially outer face 124 of shell cover 112 is providedwith a central circular aperture 126 through which access is provided tothe lock assembly 54.

Turning now to FIGS. 2, 3, 5, and 6, the operation of cap 10 will beexplained. Assuming that the cap 10 is to be removed from the fillerneck 17, the key 61 is first inserted into the slot in the lock assembly54 and turned to move pin 60 from its cap-locking position, illustratedin broken lines in FIG. 2, to its cap-removal position, illustrated insolid lines in FIG. 2. This action slides bolt 74 in the slideway 72from its position illustrated in solid lines in FIG. 5 to its positionillustrated in solid lines in FIG. 2. The head 83 of spring-likeprojection 78 is thereby cammed over the blocking ridge 81. Bolt 74 isthereby held yieldably in the position illustrated in solid lines inFIG. 2, with the locking surface 128 of its end 130 projecting throughan opening 132 in side wall 79 of cup-shaped portion 63 to engage thelocking surface 33 of one of the engaging teeth 31 provided on thegenerally cylindrical wall region 28 of closure 12. With the bolt inthis position, shell member 50 can be rotated in the cap-removaldirection (counterclockwise in FIG. 2, clockwise in FIG. 3). Since thebolt assembly 62 is locked for rotation with the shell member 50 by theengagement of projections 64 in windows 100, such rotation of shellmember 50 backs the threads 16 out of engagement with the filler neck 17and permits the cap 10 to be removed.

Once the key 61 has been rotated to rotate the pin 60 to move the bolt74 into the position illustrated in solid lines in FIG. 2, the key 61may be rotated back to move the pin 60 to the position illustrated inbroken lines in FIG. 2, so that the key 61 may be removed from the lockassembly 54. The notch 77 on the bolt head 75 is sufficiently large thatpin 60 may be in either of the positions illustrated in broken or solidlines in FIG. 2, without moving the bolt 74 from the cap-removalposition illustrated in solid lines in FIG. 2 to the cap-lockingposition illustrated in solid lines in FIG. 5. The bolt 74 is held inthe cap-removal position by the cooperation of the head 83 of projection78 with the blocking ridge 81.

Assuming now that the cap 10 is to be replaced on the filler neck 17 andlocked, threads 16 are engaged in neck 17, and the shell member 50 isrotated in the direction which advances cap 10 onto the filler neck 17(clockwise in FIG. 2 and counterclockwise in FIG. 3). As the shellmember 50 is turned, the camming surface 134 at the end 130 of bolt 74and the camming surface 35 of one of the engaging teeth 31 on thecylindrical wall region 28 of closure 12 engage, causing a thrust on thebolt 74. As this thrust increases, resilient projections 78 flexes topermit the head 83 of projection 78 to cam over the blocking ridge 81 tothe position illustrated in solid lines in FIG. 5. The bolt assembly 62no longer directly engages the closure member 12. However, continuedrotation of shell member 50 in the cap-advancing or cap-replacementdirection brings engaging surfaces 94 of fingers 92 (FIG. 3) intoengagement with driving faces 49 on the race 42 projections 47. Flexingof fingers 92 is blocked by wall 45 of race 42. This establishes thenecessary driving connection between shell member 50 and race 42 todrive the race in the cap-advancing, or cap-replacement, direction(clockwise in FIG. 2 and counterclockwise in FIG. 3). This rotation ofrace 42 is coupled through camming surfaces 46 of pockets 44 in race 42and the cooperating camming surfaces 38 of fingers 34 on the flange 32of closure 12 to advance the threads 16 of closure 12 into the fillerneck 17. When the threads 16 have been sufficiently advanced into theclosure 17, the gasket 18 seals against the lip at the axially outer endof filler neck 17, a break-away torque is reached between cammingsurfaces 38 on fingers 34 of the closure 12 and camming surfaces 46 ofthe pockets 44 on the race 42. At this torque, continued rotation of theshell member 50 results in no further rotation of the closure member 12,as the race 42 continues to ratchet on the teeth 36 due to theflexibility of the fingers 34.

Any attempt to remove the cap 10 by rotating shell portions 50, 112 whenbolt 74 is in the position illustrated in FIG. 5 causes surfaces 51 ofteeth 47 to be engaged by surfaces 95 of fingers 92. As torque isapplied to shell portion 50, fingers 92 flex and surfaces 51, 95ratchet, preventing removal of the cap.

What is claimed is:
 1. In a locking cap for a fuel tank threaded fillerneck, the cap including a gasket subject to damage due to overtighteningof the cap on the neck, a lock for controlling cap removal, a shellproviding a hand grip, a threaded closure for engaging the filler neckto close it, and first and second engaging means providing a torquelimited connection between the shell and the closure in a direction toadvance the cap into the filler neck to protect the gasket, lockactuated bolt means and cooperating additional engaging means forselectively coupling the shell directly to the closure for cap removal,the bolt means being connected to the shell for rotation therewith, andthe additional engaging means being provided on the closure.
 2. Alocking cap for a threaded filler neck comprising a closure member forengaging and closing the neck, a shell providing a hand grip andincluding a lock, and a race disposed for rotation between the shell andclosure, the race cooperating with the closure member to provide apositive connection in the cap-removal direction and a torque-limitedconnection in the cap-advancing direction, the cap further including alock-controlled bolt member, the lock-controlled bolt member beingconnected to the shell for rotation with the shell, and means forselective engagement by the bolt member, the selective engagement meansprovided on the closure, movement of the lock to the cap-removalposition permitting the bolt member to engage the selective engagementmeans to connect the shell directly to the closure, subsequent rotationof the shell in the cap-removal direction rotating the closure to permitits removal from the filler neck.
 3. A locking cap for a threaded fillerneck comprising in combination, a threaded closure member for engagingand closing the neck, a key actuable lock, a shell providing a hand gripand including means for retaining said lock, an annular race disposedfor rotation between the shell and closure, the race including firstengaging means and the closure including second engaging means forengaging the first engaging means to provide a driving connectionbetween the closure and race which is positive in the cap-removaldirection and torque-limited in the cap-advancing direction, the racefurther including third engaging means, the shell including fourthengaging means for engaging the third engaging means to provide adriving connection between the third and fourth engaging means which ispositive in the cap-advancing direction and torque-limited in thecap-removal direction, bolt means mounted for rotation with the shell,and fifth engaging means on the closure, the bolt means being actuableby key actuation of the lock for movement into engagement with the fifthengaging means to couple the bolt means and shell directly to theclosure to permit removal of the cap from the filler neck.
 4. The cap ofclaim 3 wherein the third engaging means comprises at least one radiallyinwardly projecting engaging tooth on a radially inwardly facing surfaceof the race, the tooth including an inclined camming surface and alocking surface, the shell comprises a molded plastic shell portion, andthe fourth engaging means includes at least one flexible fingerintegrally and unitarily molded to the shell portion for projecting intoengagement with the tooth, the finger including a camming surface and alocking surface, the camming surfaces of the tooth and finger and theflexibility of the finger cooperating to provide the torque-limitedconnection between the race and shell in the cap-removal direction andthe locking surfaces of the tooth and finger cooperating to provide thepositive connection between the race and shell in the cap advancingdirection.
 5. The cap of claim 4 wherein there are a pair of suchflexible drive fingers, the fingers being mounted at generallydiametrically opposed points on the shell portion. the fingers extendinggenerally along chords of a circle defined by said shell portion andterminating at generally diametrically opposed points on the shellportion.
 6. The cap of claim 3 wherein the bolt means includes acup-shaped member extending axially inwardly from the shell into theclosure, the cup-shaped member providing a slideway which extendsgenerally chordally across the cup-shaped member, a bolt slidable in theslideway between a position in engagement with the fifth engaging meansto permit cap removal and a position out of engagement with the fifthengaging means to prevent removal of the cap, the cup-shaped memberhaving a generally cylindrical side wall including means defining anopening through which the bolt projects when in position to engage thefifth engaging means, the bolt means further including means providing ayieldable spring extending from the bolt, and stop means provided on thegenerally cylindrical wall of the cup-shaped member, the yieldablespring including a head cooperating with the stop means yieldably tohold the bolt in either of said two positions.
 7. The cap of claim 6 inwhich the bolt includes a bolt end having a locking surface and acamming surface, and the fifth engaging means includes an engaging toothon the closure, the engaging tooth having a locking surface and acamming surface, the locking surfaces of the bolt and fifth engagingmeans tooth cooperating when the bolt is in the cap-removal position andthe shell is rotated in a cap-removal direction to permit removal of thecap, and the camming surfaces of the bolt and fifth engaging means toothcooperating when the bolt is in the cap-removal position and the shellis rotated in a cap-advancing direction to overcome the spring force anddrive the spring head over the stop means and move the bolt to thecap-locking position.
 8. The cap of claim 7 in which the lock includes adrive pin and the bolt includes a head defining a slot for receiving thedrive pin, rotation of the key in the lock in one direction moving thepin in the slot to move the bolt to the cap-removal position, the slotbeing sized to permit rotation of the key in the opposite directionwithout moving the bolt back to the cap-locking position to permitremoval of the key from the lock while the bolt remains in thecap-removal position.
 9. In a locking cap for a fuel tank threadedfiller neck, the cap including a gasket subject to damage due toovertightening of the cap on the neck, a lock for controlling capremoval, a shell providing a hand grip, a threaded closure for engagingthe filler neck to close it, and first and second engaging meansproviding a torque-limited connection between the shell and the closurein a direction to advance the cap into the filler neck to protect thegasket, third engaging means positively drivingly connected to theclosure in the cap-removal direction and fourth engaging means connectedto the shell, the third and fourth engaging means positively engagingone another in the cap-advancing direction and cooperating to provide atorque-limited connection in the cap-removal direction, lock actuatedbolt means and cooperating fifth engaging means for selectively couplingthe shell directly to the closure for cap removal, the bolt means beingconnected to the shell for rotation therewith, and the fifth engagingmeans being connected to the closure for rotation therewith.
 10. The capof claim 9 wherein the third engaging means comprises at least oneradially inwardly projecting engaging tooth formed on a radiallyinwardly facing surface of the race, the tooth including an inclinedcamming surface and a locking surface, the shell includes a moldedplastic shell portion, and the fourth engaging means includes at leastone flexible finger integrally and unitarily formed on said moldedplastic shell portion, the finger projecting into engagement with thetooth, the finger including a camming surface and a locking surface, thecamming surfaces of the tooth and finger and the flexibility of thefinger cooperating to provide the torque-limited connection between therace and shell in the cap-removal direction and the locking surfacesthereof cooperating to provide the positive connection between the raceand shell in the cap-advancing direction.
 11. The cap of claim 9 whereinthe bolt means includes a cup-shaped member extending axially inwardlyfrom the shell into the closure, a slideway provided in the cup-shapedmember to extend generally chordally across the cup-shaped member, abolt slidable in the slideway between a position in engagement with thefifth engaging means to permit cap removal and a position out ofengagement with the fifth engaging means to prevent removal of the cap,the cup-shaped member having a generally cylindrical side wall includingmeans defining an opening through which the bolt projects when inposition to engage the fifth engaging means, the bolt means furtherincluding means providing a yieldable spring extending from the bolt,and stop means provided on the generally cylindrical wall of thecup-shaped member, the yieldable spring including a head cooperatingwith the stop means yieldably to hold the bolt in either of said twopositions.
 12. The cap of claim 11 in which the bolt includes a bolt endhaving a locking surface and a camming surface, and the fifth engagingmeans includes an engaging tooth on the closure, the engaging toothhaving a locking surface and a camming surface, the locking surfaces ofthe bolt and fifth engaging means tooth cooperating when the bolt is inthe cap-removal position and the shell is rotated in a cap-removaldirection to permit removal of the cap, and the camming surfaces of thebolt and fifth engaging means tooth cooperating when the bolt is in thecap-removal position and the shell is rotated in a cap-advancingdirection to overcome the spring force and drive the spring head overthe stop means and move the bolt to the cap-locking position.
 13. Thecap of claim 12 in which the lock includes a drive pin and the boltincludes a head defining a slot for receiving the drive pin, rotation ofthe key in the lock in one direction moving the pin in the slot to movethe bolt to the cap-removal position, the slot being sized to permitrotation of the key in the opposite direction without moving the boltback to the cap-locking position to permit removal of the key from thelock while the bolt remains in the cap-removal position.
 14. The cap ofclaim 10 wherein there are a pair of such flexible drive fingers, thefingers being mounted at generally diametrically opposed points on theshell portion, the fingers extending generally along chords of a circledefined by said shell portion and terminating at generally diametricallyopposed points on the shell portion.
 15. A locking cap for a threadedfiller neck comprising a closure member for engaging and closing theneck, a shell providing a hand grip and including a lock, and a racedisposed for rotation between the shell and closure, the racecooperating with the closure member to provide a positive connection inthe cap-removal direction and a torque-limited connection in thecap-advancing direction, the race further including engaging means andthe shell including a shell portion for providing at least one flexibledrive finger for engaging the engaging means on the race to provide apositive connection in the cap-advancing direction and a torque-limitedconnection in the cap-removal direction, the cap further including alock-controlled bolt member, the lock-controlled bolt member beingconnected to the shell for rotation with the shell, and means forselective engagement by the bolt member, the selective engagement meansprovided on the closure, movement of the lock to the cap-removalposition permitting the bolt member to engage the selective engagementmeans to connect the shell directly to the closure, subsequent rotationof the shell in the cap-removal direction rotating the closure to permitits removal from the filler neck.
 16. The cap of claim 15 wherein thebolt member includes a cup-shaped member extending axially inwardly fromthe shell into the closure, a slideway provided in the cup-shaped memberto extend generally chordally across the cup-shaped member, a boltslidable in the slideway between a position in engagement with the fifthengaging means to permit cap removal and a position out of engagementwith the fifth engaging means to prevent removal of the cap, thecup-shaped member having a generally cylindrical side wall includingmeans defining an opening through which the bolt projects when inposition to engage the fifth engaging means.
 17. The cap of claim 16wherein the bolt member further includes means providing a yieldablespring extending from the bolt, and stop means provided on the generallycylindrical wall of the cup-shaped member, the yieldable springincluding a head cooperating with the stop means yieldably to hold thebolt in either of said two positions.
 18. The cap of claim 17 in whichthe bolt includes a bolt end having a locking surface and a cammingsurface, and the fifth engaging means includes an engaging tooth on theclosure, the engaging tooth having a locking surface and a cammingsurface, the locking surfaces of the bolt and fifth engaging means toothcooperating when the bolt is in the cap-removal position and the shellis rotated in a cap-removal direction to permit removal of the cap, andthe camming surfaces of the bolt and fifth engaging means toothcooperating when the bolt is in the cap-removal position and the shellis rotated in a cap-advancing direction to overcome the spring force anddrive the spring head over the stop means and move the bolt to thecap-locking position.
 19. The cap of claim 18 in which the lock includesa drive pin and the bolt includes a head defining a slot for receivingthe drive pin, rotation of the key in the lock in one direction movingthe pin in the slot to move the bolt to the cap-removal position, theslot being sized to permit rotation of the key in the opposite directionwithout moving the bolt back to the cap-locking position to permitremoval of the key from the lock while the bolt remains in thecap-removal position.